Heretofore, the following has been known as this kind of vehicle interior structure (for example, see Patent Reference 1). For example, in Patent Reference 1, an example of a vehicle interior sound regulation apparatus is disclosed. In the example of Patent Reference 1, an acoustic lens is provided in a headrest side portion of a front seat, such that the sound of an occupant sitting on a rear seat can be clearly heard by an occupant sitting on the front seat.
Patent Reference 1: Japanese Utility Model Application Laid-Open (JP-U) No. H4-71558
Patent Reference 2: Japanese Patent Application Laid-Open (JP-A) No. H11-355748
Patent Reference 3: JP-A No. S63-195043
Patent Reference 4: JP-U No. S61-1515